From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Xuanqiang Luo <xuanqiang.luo@linux.dev>
Cc: linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, alex.aring@gmail.com,
stefan@datenfreihafen.org, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
horms@kernel.org, Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Subject: Re: [PATCH net v1] mac802154: drain mac_wq before unregistering interfaces
Date: Mon, 31 Aug 2026 10:10:05 +0200 [thread overview]
Message-ID: <87jyp6btia.fsf@bootlin.com> (raw)
In-Reply-To: <20260828101905.26865-1-xuanqiang.luo@linux.dev> (Xuanqiang Luo's message of "Fri, 28 Aug 2026 18:19:05 +0800")
On 28/08/2026 at 18:19:05 +08, Xuanqiang Luo <xuanqiang.luo@linux.dev> wrote:
> From: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
>
> ieee802154_unregister_hw() unregisters the wpan netdevs before
> destroying mac_wq. The RX path stores the receiving sub-interface
> (sdata) in the queued MAC command descriptor without taking a
> reference to the netdev.
>
> If mac802154_rx_mac_cmd_worker() runs after the netdev has been freed,
> it dereferences the stale pointer and triggers a KASAN
> slab-use-after-free:
>
> BUG: KASAN: slab-use-after-free in mac802154_rx_mac_cmd_worker+0xc0/0x498 [mac802154]
> Read of size 8 at addr ffff0000c6db0ba8 by task kworker/u16:3/61
> ...
> Call trace:
> show_stack+0x20/0x38 (C)
> dump_stack_lvl+0x78/0x90
> print_address_description.constprop.0+0x88/0x398
> print_report+0xa8/0x278
> kasan_report+0xa8/0xf8
> __asan_load8+0x9c/0xc0
> mac802154_rx_mac_cmd_worker+0xc0/0x498 [mac802154]
> process_one_work+0x334/0x8b8
> ...
> Allocated by task 630:
> kasan_save_stack+0x2c/0x58
> kasan_save_track+0x20/0x40
> kasan_save_alloc_info+0x40/0x58
> __kasan_kmalloc+0xa0/0xb8
> __kvmalloc_node_noprof+0x1e8/0x588
> alloc_netdev_mqs+0x74/0x7f0
> ieee802154_if_add+0xac/0x630 [mac802154]
> ieee802154_register_hw+0x31c/0x3d0 [mac802154]
> fakelb_add_one+0x250/0x318 [fakelb]
> ...
> Freed by task 652:
> kasan_save_stack+0x2c/0x58
> kasan_save_track+0x20/0x40
> kasan_save_free_info+0x4c/0x78
> __kasan_slab_free+0x60/0x90
> kfree+0x194/0x478
> kvfree+0x44/0x60
> netdev_release+0x4c/0x68
> device_release+0xac/0x130
> kobject_cleanup+0x84/0x248
> kobject_put+0x98/0xf8
> netdev_run_todo+0x3a0/0x5e0
> rtnl_unlock+0x18/0x30
> ieee802154_unregister_hw+0x48/0x90 [mac802154]
> fakelb_remove+0xe8/0x148 [fakelb]
>
> After killing local->tasklet, drain mac_wq before calling
> ieee802154_remove_interfaces() so pending work completes before the
> interfaces are unregistered. Do this without holding rtnl because scan
> and beacon workers acquire it themselves.
>
> Fixes: d021d218f6d9 ("mac802154: Handle received BEACON_REQ")
> Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Missing Cc: stable.
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Thanks,
Miquèl
next prev parent reply other threads:[~2026-08-31 8:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-28 10:19 [PATCH net v1] mac802154: drain mac_wq before unregistering interfaces Xuanqiang Luo
2026-08-31 8:10 ` Miquel Raynal [this message]
2026-09-01 1:24 ` Xuanqiang Luo
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